The present invention relates to dual chalk line markers and, more particularly, to an improved, adjustable, dual chalk line marking apparatus that can easily mark chalk lines that vary in their spacing with respect to each other, while eliminating the need for any separate measuring tools.
Chalk line marking devices have been found useful in the building, construction, and roofing industries. The roofer often uses a chalk line marker to evenly space shingles upon a roof. In building a house, for example, a construction worker often uses a chalk line marker to accurately space joists and floor supports while securing sheeting.
In one embodiment of the present invention, a chalk line marking device features a double pair of juxtaposed chalk line dispensers that are each affixed to a corresponding base. A chalk line is dispensed from the fixedly spaced dispensers by means of respective crank handles. A stationary ruler is disposed adjacent each dispenser allowing each dispenser to register its position about a work surface adjacent its corresponding ruler. The base is secured once a chalk line position is determined. The chalk lines are deposited upon a work piece by first striking the chalk lines in one position and then sliding the chalk lines to a second position where they are struck again.
In another embodiment, the chalk line dispensers can comprise an internal spring so that the chalk lines can automatically return into the dispenser housing after having been extracted therefrom.
The present invention is based on the discovery that providing an apparatus for easily varying the width of the chalk lines provides a means by which markings can be made for different joist spacing, as well as different sizes of shingles without the use of extraneous tools and/or measurements.
The present invention features an adjustable chalk line device wherein a single pair of chalk line dispensers can be adjustably moved along the base, thus varying the distance between them. The opposite end of the chalk line is secured to an opposite base by a clip against a spring-bias. A built-in ruler is slidably extracted from the base and acts as a guide to position the dispensers with respect to the work surface. The rulers can be locked in place to allow the worker to move the device to a new location, and subsequently strike a new set of chalk lines.
In U.S. Pat. No. 5,063,681 issued to Bradley on Nov. 12, 1991 for DUAL CHALK LINE MARKER, a dual chalk line marking device is illustrated. The dual chalk lines are dispensed from a spool by a hand crank. The chalk lines are spaced a given, fixed distance apart by a first spreader unit attached to the spool. A second, movable spreader unit is withdrawn from the first spreader unit to advance the dual chalk lines a given distance from the spool.
The present invention is a dual chalk line marker device. The line marker device comprises a housing or base in which are disposed two spaced-apart spools. Each spool contains a quantity of chalk line and is movable with respect to the housing or base, wherein the width of separation between the chalk lines can be varied easily. A ruler bar unit is movably distanced from the housing and receives the dual chalk lines; a given length of chalk lines can be metered from the housing or base. The distal end of each chalk line comprises a clip that attaches to the ruler bar unit at indexed, slotted stations, which allows the lines to be anchored a predetermined width with respect to the adjustable spools. The spools comprise crank handles for extracting and retracting a given amount of chalk line. They can also be constructed with an internal spring wherein chalk lines can be extracted from the spools against the spring force and will be automatically retracted under the spring biasing.
Both the housing and the ruler bar unit comprise a double-sided ruler that is slidably movable therein in order to extract it. The double-sided rulers allow the dual line chalk marker device to be positioned with respect to a work surface. Both the housing and the ruler bar unit comprise a slot in which a spring biased tab rides. Each tab is attached to its respective double-sided ruler. Depressing the tab allows its respective, double-sided ruler to move within the slot. Releasing the tab locks the respective ruler in place.
It is an object of this invention to provide an improved dual chalk line marker device.
It is another object of the invention to provide a dual chalk line marker device that is adjustable in order to vary the spaced-apart width between the chalk lines, while supplying a means by which successive sets of lines may be struck without aid of a separate measuring device or tool.